I exercise at the gym once a week. Does this interfere with training?

Does not interfere.
JacaCoachTEAM gives you the opportunity to perform a “gym” type training unit, further implementing a training plan aimed at developing endurance sports.
Such a unit will be appropriately included in the training plan.
Note: If you are able to do 4 training sessions a week (one of which is the gym), tell your trainer that you can train 3 days a week and training for endurance sports will be planned on these days.